Human immunodeficiency virus-1 infection of macrophages in vitro neither induces tumor necrosis factor (TNF)/cachectin gene expression nor alters TNF/cachectin induction by lipopolysaccharide.
The synthesis of tumor necrosis factor (TNF)/cachectin was assessed in primary monocyte-derived macrophage (MDM) cultures after in vitro infection with a macrophage-tropic strain of HIV-1 (HTLV-IIIBa-L/85). Productive and cytopathic infections in MDM cultures were established using a high multiplicity of infection (m.o.i. = 3) under conditions that minimized endotoxin contamination. Culture supernatants were tested for TNF/cachectin activity by L929 cell cytotoxicity assay, and TNF/cachectin mRNA was assessed by a sensitive PCR amplification technique that could detect between 1 and 10 cells fully activated for TNF/cachectin expression. Unstimulated MDM cultures produced no detectable levels of TNF/cachectin activity or mRNA, consistent with previous demonstrations that production of this cytokine by macrophages is an inducible and not a constitutive event. HIV-1 infection failed to induce detectable TNF/cachectin activity or mRNA in these unstimulated cultures. In addition, the responsiveness of macrophages to lipopolysaccharide (LPS) induction of TNF/cachectin production was assessed in dose-response and kinetic experiments. No differences between infected and uninfected cultures were discernable. These results demonstrate that productive and cytopathic infection with a macrophage-tropic strain of HIV-1 does not alter the regulation of TNF/cachectin expression in macrophages.
Munis
J R
JR
Department of Medicine, University of California, San Diego.
Richman
D D
DD
Kornbluth
R S
RS
D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D015497:HIV-1 / Q000472:pathogenicity*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics*
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha